The TARDIS wasn't mad.
No not angrymadfrustratedannoyed.
ANNOYED!
That was it! Emotions were weird, their names even weirder. Too many variations, slight changes meaning something else entirely. Absolutely strange.
Her mood was justified. The TARDIS liked justified. It gave a everything a reason. Her Thief liked justified. Her Thief liked River too.
The Doctor also liked words. Metaphorssimiliespersonification. He liked using different variations of describing things. Maybe he wanted to make things easier to understand or maybe he just liked talking.
With all those words, maybemaybemaybe Her Thief could have come up with a different name for River The Golden Haired One. TARDIS usually liked River. Her Child was always welcome. Especially when she took care of The Doctor. But not now. Ohnotnow.
Because everyone knew that the TARDIS was his girl. Not River.
Honestly. What was he thinking?